Loop antenna



Dec. 25, 1928.

T. C. DEUTSCHMANN LOOP ANTENNA Filed Jan. 2 1924 2 Sheets-Sheet 1 Dec. 25, 1928.

T. c. DEUTSCHMANN LOOP ANTENNA 2 Sheets-Sheet 2 Filed Jan. 24, 1924 Patented Dec. 25, 1928.

UNITED STATES PATENT OFFHQE.

LOOP ANTENNA.

Application filed January 24, 1924. Serial No. 688,320.

This invention relates to a loop antenna such as might be used in the reception of wireless messages, and more particularly to a loop adapted for indoor use.

An object of the invention is to produce a 100 antenna of a desired size and capacity, an of simple structure, that may be knocked down for the purpose of shipping or storage, and which may be erected or knocked down by an unskilled person in a very few moments and without the aid of tools.

A further object of the invention is to produce a loop antenna of a given capacity and of such arrangement that if the full capacity thereof is not'required to receive a message to a given point, certain portions of the loop, approximating the surplus capacity, may be cut out. I

Another and important object of the invention is to produce a loop antenna having the above qualities together with the fact that the arrangement of the wires forming the loop is such, that there are no dead ends in the portion of the loop in use, and consequently detrimental electrical capacity so common in the loops at present in use wherein dead ends are present, is eliminated.

A still further object of the invention is to produce a loop antenna of this class, having means to take up undue slack of the wires of the loop when the said loop is knocked down, the said means automatically efl ecting said take up upon the collapsing movement of certain of the parts of the loop frame. An object of the invention is to provide a loop antenna with a direction indicator, which upon an initial setting, enables an operator to rapidly point the loop in approximately the direction of a station it is desired to hear when the approximate direction of said station is known to the operator.

The invention consists in certain novel features of construction and arrangement which will be fully understood from a description of the drawings and theclaimshereinaftergiven.

Of the drawings:

Figure. 1 represents in side elevation, a loop antenna embodying the present invention, as it would appear when erected and ready for use.

Figure 2 an edge view looking toward the right Figure 1.

Figure 3 a diagram showing'the preferred system of wiring the loop, so that the entire loop, or certain sections only, may be used, and to clearly show the absence of dead ends in the portion or portions used.

Figure 4 a rear side view of Figure 1 showing the loop frame collapsed and detached from the stand and direction indicator, preparatory to shipping or storing.

igure 5 is a view taken on approximately; the line 55 Figure 1 showing the stand and direction indicator in position for use.

Figure 6 a view similar to Figure 5 but showing the indicator removed and .the stand collapsed preparatory to shipping or storing.

Figure 7 a fragmental view of the loop frame party broken away, and showing the means for securing the frame in extended position.

Figure 8 a vertical longitudinal viewof the frame and portion of the base as seen in Figure 1. 1

Like characters represent like parts throughout the several figures of the drawings.

Referring to the drawings:

The drawings herewith illustrate the invention in the preferred form, but it will be undestood that slight changes might be made therein without departing from its spirit and scope.

As it is an object of the invention to provide a loop antenna that may be rapidly erected or knocked down, the. loop frame 10, direction indicator 11, and stand or rest 12, are made detachable as seen in Figure 4 of the drawings.

The stand 12 is composed of the members 13 and 14, the member 13 having fast therewith the tubular member 15 which is adapted to receive and form a bearing for the spindle 16 of the loop frame 10.

The member 14 is made in the form of an arch, and is somewhat longer than the member 13, so that, the said member 13 may be swung thereunder and in line therewith, when it is desired to store or ship the loop, as seen in Figure 6 of the drawing.

The member 14 has a hole 17 through which the tube 15 extends, the said hole being countersunk to receive a spring 18, the upper portion of which bears against a washer 19, which is held in place on the member 14 by the nut 20, engaging threads on the tube 15, to thereby frictionally hold the members 13 and 14, in a given relative position.

Surrounding the tube 15, is the hub of the disk, or direction indicator plate 11, which is adapted to be securedto'the'tube 15 by means of the set screw 21.

This disk has circularly arranged graduations thereon, and when initially secured on the tube 15 with the'zero pointing north, the loop 10 may be rapidly turned to point in; the direction of the, or a, desired station, if the compass direction of that stationis known approximately, thus saving considerable time inlocating-a station.

Themeniber 14'at one end thereof, is provided with a levelling device consisting of a foot 22, revolubly'secured to the end of a screw 23, whiclrengages a nut 24, fast with themember 1'4, he said screw being provided with a check'nut t'o lock it in'the desired position;-

The spindle 16 depends from-the plate26 which for'mspart of the base for the loop frame lOyand has fast therewith the separableblocks 27 and 28,-of insulating material, between which the several wires of the loop pass.

Thern'a'in portion of the loop 'framecomprises the uprights 30 and"31 which are se cured to the block 28 by brackets 32,-or in any suitable manner, and are secured together at their topend's by'cheek pieces'33 and 34, and a cover 35, suitably secured to said ieces; aiidwhi'cn has a hcie 36 therein for a? urpose vobe described.

The said uprights are so spaced as to pro vide a slot 37, in which the extension 38 islongitudin'a'lly slidalble,-a'nd inwhichit' is guided andpr'evented from lateral; movement by means of the fins 39 entering the'grooves' 40, and the hole 36 in the cover '35.

At its upper end the extension 38 is providedwit'lflabross member 41 which'lia's fast to it the blocks42 and 43'between which the severalwires of-thc loop are laid and secured.

At its lower end the'said extension has a screw 44 fast therewith, which is adapted to be engaged by the thumb nut 45, a washer 46, being provided to normally bear against the cheek piece 33 when the frame 10 is extended or when the screw 44 is in the slot 47 of' the piece 33, and the thumb nut is set up to clamp the said' extensionin its raised position;

Thesaid' extension arms 50, at their inner ends" see Figure 7-, are housed within the cheek pieces and cover, and pivoted at 51, eachhavingat its outer end'a cross member 52 and clamp blocks to grip the wires in a man ner similar to those of the extension 38.

If desired, the several wires of the loop may be securedfrom entanglement by the application-of wire separating clamp blocks 53.

Each of the" brackets 32 has an upward extension 54 to which is pivoted one arm of a pair", and between the free'endsof eachpa'i'r of arms'55,-and 56,*isa roller 57, adapted to be held in contact with the wires on its respect'ive side by means of the springs 58, and'5'9.

\Vhen the frame 10 is in extended position,.the tension lot the several loop wires is such, that the arms 55, an d 56 will be held in the positions shown in Figure 1 against the action of the springs 58, and 59.

To'knoch down the antenna, the nut 45 will be released and the extension 38 lowered,

whiclr action automatically causes the side extension 50' to swingdb'wnwa'r'dly on their pivots 51 and simultaneonsl as'slack occurs in the wires between the cross-members" 52 and the bloclts27fa'nd'28, tlie pairsof-arrns 55 and 56 willbe drawn towardeach other. by the springs-58'and59 thus takingup the slack in" those wires ina'ma'n'ner' whereby they'will be snugly stowed from'harm and-possible entan lemen't with-other objects.

By releasing the set screw 21', the indicator disk 11, may'be'removed from the-tubular member 15,=but not till the spindle 1'6,'-and the frame- 10, have'b'een removed, which has been done asillustrate'd in Fig11re4"of the draw ings. v

To further facilitate in the shipping'of-the complete antenna, the stand 12 is madeto fold as seen in Figure 6=cf the-drawings, wherein the member 13"lia's been sWung-on"1ts pivot 15, under the arch of the'member'mand in line therewith? i Asit is*aii'o'bj ect-ot this invention to'el-iminate dead e'ndsfi andconsequently dlsturb ing eleetricalinflue'nces", and at the same time utilize the f whole or portions of l the antenna for receiving purposes, arrangements are hereinmade whereby that result is accomplished.

Viewing the diagram Figure 4 ,-a, b, c, and (1'' represent predetermined lengths of antenna wire the ends of each of which are suitably connected to binding posts in such manner that by coupling certain binding posts the full'capacity'of the antenna is available for use, while if certainposts'are coupled and others not coupled, only a fraction of the fullantenna' capacity is available- In other words if an antenna shonld'be divided into four sections and thecapacity required for a given purpose could be represented by the section a, lead wires running to the set, not shown, would be connected to the posts a, and f.

If two'sections'aand'b, were requi'red,-the lead wires would be'connected to-the posts 6, and g, and the posts 9 and h, would beconnect'ed by the coupling m, thus completing the circuit between sections a',=andb.

If three sections were required=the coupling n, would be engaged with post 9 ,-andthe lead wire" running togg-would be moved to post p, and when entire capacity of loop'is required coupling 8', will be engaged with post p and thedead'wireshiftcd'to w.

With this arrangement it will be readily seen that there are no dead ends in the section or sections in use, as is the case at present where antennae are made up of one wire having a plurality of taps therein for the purpose of cutting down capacity.

It is known that antennae have been used which were collapsible or could be folded in comparatively small compass, but in such instances slack taking in the antenna wire was not provided for, and trouble resulted in wire entanglement and injury, the devices were not stable, and therefore unsatisfactory.

It is not known that a loop antenna has ever been used, wherein the loop frame could be collapsed 0r knocked down by a single operation which also automatically took care of antenna wire that would otherwise be subject to damage.

Nor is it known that a loop antenna has ever been used that did not have one or more dead ends, or that had a plurality of normally disconnected sections which. could be coupled together for the capacity required, up to and including the full capacity of the loop.

In view of the above assertions, it is not the intention to limit the invention to the precise system or arrangement of wiring, as it will be understood that changes might be made therein to suit the occasion of use, without departing from its spirit and scope.

Having described the invention I claim:

1. In a' device of the class described, a stand adapted to be collapsed; an antenna frame pivotally and detachably mounted on said stand and comprising uprights so arranged as to provide a housing for an extension arm; an extension arm adapted to be housed by said uprights; said uprights having laterally extending arms adapted to be moved into parallelism with said uprights; means coacting with said uprights and said arms whereby antenna wire may be secured thereto; antenna wire secured to said means; means to simultaneously release said arms whereby said extension arm may be housed between said uprights and said laterally extending arms moved into parallelism with said uprights; and means to automatically take up slack in said antenna wire when said extension arm is being housed.

2. In a device of the class described, a stand adapted to be collapsed; an antenna frame pivotally and detachably mounted on said stand and comprising uprights so arranged as to provide a housing for an extension arm; an extension arm adapted to be housed by said uprights; arms laterally extending from said uprights and adapted to be moved into parallelism therewith; means carried by said uprights and said arms to which antenna Wire may be secured; antenna wire secured to said means; a clamp device adapted to release said arms when said frame is to be collapsed; and spring controlled arms adapted to take up slack in said wire when the said frame is being collapsed.

3. In a device of the class described, a stand adapted to support an antenna frame; an antenna. frame pivotally mounted on said stand and comprising an upright and arms radiating therefrom, said arms being adapted to be folded toward said upright; means to secure antenna wire to said frame; antenna wire secured to said frame; and take up means comprising pivoted members normally under spring control and held from operative movement by said wires and adapted to be folded toward said upright by said control when said arms are folded whereby slack wire incidentto the complete folding of said arms is taken up.

4. In adevice of the class described, a stand adapted to support an antenna frame; an antenna frame supported by said stand and comprising a pair of spaced uprights having provision therebetween for the reception of an extension arm; an extension arm adapted to be moved longitudinally between said uprights; means to retain and guide said arm between said uprights; laterally extending arms pivotally mounted adjacent the upper ends of said uprights and adapted to fold downwardly parallel thereto; means to secure a plurality of loops of antenna Wire to said frame; a plurality of take up members pivoted adjacent the bottoms of said up rights and adapted to fold upwardly toward said uprights when said laterally extended arms are folded and springs adapted to actuate said take up members.

5. A collapsible loop antenna frame comprising diagonal supporting members, one of which comprises two telescoping parts adapted to telescope one within the other substantially throughout their entire length, a second diagonal member comprising two arms hinged to one end of one of the telescoping parts and adapted to be folded in the plane of the loop parallel to the telescoping parts.

Signed by me at Boston, Mass, this 14th day of Jan, 1924.

TOBE C. DEUTSOHMANN. 

